As is perhaps best stated by German Pat. No. 932,410 issued Sept. 1, 1955 found in the library of the Office of Patents and Trademarks and the Examiner's foreign art for Class 244, subclass 130 of the U.S. Office of Patents and Trademarks, one should consider the plot of the sum of displacement cross sections of an airplane to provide the optimum area diagram therefor that leads to reduced wave drag. As one skilled in the art known there is a one to one correspondence between airplane area distribution and its wave drag.
The object of some skilled in the art from the teaching of such has been to not only "area rule" an airplane for best wing-body airflow interaction, but to use external stores and podded engines to effect the best area distribution; i.e., one that may be plotted like that of a surface of revolution rising from the nose and reaching a highpoint about midway and decreasing to zero beyond the empennage. The object being to fix appendages so as to eliminate stepwise increases or decreases, as well as repeated changes in the increase or decrease of the area diagram as precipitated by the sum of displacement cross sections which lie in common and consecutive airplane cross-sectional planes.
On the other hand, the main body of those skilled in the art have reacted to the problem of airplane area distribution by designing the airplane clean (without appendages). Others have tried to minimize the problem of airplane area distribution by area ruling and selecting power plants to obtain optimum performance at a particular design point. The SST is an example of this approach. With certain airplanes, appendages thereto must take into account e.g. limitations. In such instances there has been heretofore little opportunity to area rule the design. Instead designers have employed fairings, etc., to minimize aerodynamic problems of the combination of appendages to the airplane.
No one prior to this invention has studied the concept, as first explored in the aforesaid German Patent since it became part of the knowledge for one skilled in the art to see if with the concept one could improve an airplane performance throughout its flight regimes from take off to landing.
It is believed, as with many things today, that as long as one has unlimited energy resources, one merely applies more energy to overcome any drag associated with irregularities of airplane surface area. It is in this area that this invention shall attempt to disclose more practical cost and energy effective design variables to those skilled in the art.